Updating 1968 Chevrolet C-10 Engine - Restoration Rehab

After purchasing my ’68 C10, it became obvious pretty quickly that the engine was in need of a little attention. Not only in the looks department, however, but in the performance aspect as well. Don’t get me wrong, it pulled strong and ran like a clock, but it just didn’t do it with any quickness of expedition. Couple that with the emaciated performance provided by the three-on-the-tree transmission and suffice it to say I was going to be making some changes to the powertrain in the C10.

2/42Here’s the stock 307 in all its glory. With decent compression and positive results from the leakdown test, we decided to leave it be for the time being, but not alone.

Before I chose what road to go down though, it would be necessary to see what kind of shape the engine was actually in. I ran a compression test, dropped the pan, and checked the rings/cylinder seal with a leakdown tester from Summit Racing and was pleased to find out that the motor actually checked out pretty well. It also didn’t knock or smoke while running, another good sign. The previous owner mentioned that he only drove it occasionally to haul large items to the dump or to pick up something from the hardware store so I figured it probably hadn’t seen much abuse. Upon further investigation (okay it was one of the first things I noticed!) was the fact that the engine was not the usual Chevy Orange for the period, but Chevy Corporate Blue, a color not adopted until 1977 when GM began their “corporate engine” edict. I ran the numbers and sure enough, they matched the truck, being identified as a 307ci motor from 1968. A closer look revealed that the timing cover, valve cover, head, and intake gaskets were not painted, which told me that someone hadn’t just inadvertently decided to paint the whole kit and caboodle (as I was about to!), but painted everything in pieces. This means that at one time in the past forty some-odd years, the engine was taken apart, at least that far. Long story short, someone rebuilt the 307 at some point, most likely between 1977 and 1982. Either that or they rebuilt it last year and painted it blue for some strange reason, but I digress.

That said, I figured I had a pretty sound foundation to build a super-mild, little hot rod engine for the C10 until my future plans for the drivetrain come closer to fruition.

3/42

My original plan was to leave the motor stock and to bolt on Holley’s new Avenger EFI system once the truck was up and running with the new T5 transmission installed. That was a great plan, however, until I found myself at a crossroads while McLeod built my clutch. With the truck sitting, I figured I wouldn’t get a better opportunity than that to detail the engine. I set off on my beautification phas e by dismantling the engine down to the block and heads to get rid of the Corpo Blue and return it to its original Chevy Orange guise.

Though I planned on making some contemporary upgrades, I wanted to make all of them in a conscious effort to maintain the late ’60s period of the truck; nothing too out of place under that hood, at least in an aesthetic sense. I stuck with orange, grey, and black under the hood in order to build a hot rod motor that comes across as though it were factory, at first glance anyways. The end result really speaks for itself when compared to the initial motor, and the added power and performance really woke the truck up and made it transform from a junkyard dog to a highway hauler. CCT